Vessels go round, heading off south (4)
I believe the answer is:
urns
'vessels' is the definition.
(urn is a kind of vessel)
'go round heading off south' is the wordplay.
'go round' becomes 'turn' (both can mean to rotate).
'heading off' means to remove the first letter.
'south' becomes 's' (abbreviation).
'turn' with its first letter taken off is 'urn'.
'urn'+'s'='URNS'
(Other definitions for urns that I've seen before include "Funereal vases" , "Large vases or pots" , "Burial vases" , "Vase-shaped vessels" , "Large pots for tea" .)